The present invention relates generally to the interconnections of roof panels and the securement of the roof panels to a supporting structure.
More particularly, the invention relates to a clip assembly which will provide superior pull-up strength and permit the roof panels to contract or expand due to changes in temperature without damaging the interconnection joint in such a manner as to create leakage problems.
The corrugated type of roof construction considered to be secured by the clip assembly of this invention typically has previously been clamped to a purlin member by direct application of a threaded fastener through the valley of a corrugation and into the purlin. This produces an obvious problem in that the joint must now be secured from moisture by a sealing cap or through the use of a sealing washer. The joint also will not permit relative expansion and contraction of the panels without damaging the panel in the area of the joint.
Other prior art devices relative to a roof hold down fastener utilize a hold down clip device which is interleaved between abutting and crimped lips on adjacent roof panels. The clip is then secured directly to a purlin by rigidly clamping a base portion of the clip thereto and then crimping the abutting edges of the roof panels to an upstanding web formed integrally on the clip. This type of construction has likewise been deficient in its capability to harmlessly allow expansion and contraction of the roof panels.
Other problems that are inherent in the prior art methods and devices for securing roof panels to a supporting structure include their failure to prevent condensation from forming on the clip or the fastener. Even if the joint is properly sealed, the difference in temperature between the outer surface of the building and the inner surface of the building will create condensation and moisture on the clip and fastener located within the building.